Step Outputs

Values generated in a step can be referenced by other steps. Store them in the $COLLABOPS_OUTPUT file as key=value pairs, and read them with $\{\{ steps.<id>.outputs.<key> \}\}.

Basic Usage

steps:
  # 1. Store output values — you must specify an id
  - name: prepare
    id: meta                   # Identifier for referencing from other steps
    image: node:18
    run: |
      # Store as key=value in $COLLABOPS_OUTPUT
      echo "version=1.2.3" >> $COLLABOPS_OUTPUT
      echo "timestamp=$(date -u +%Y%m%dT%H%M%S)" >> $COLLABOPS_OUTPUT

  # 2. Reference output values — using steps.<id>.outputs.<key> format
  - name: use-output
    image: alpine:3.19
    run: |
      echo "Version: ${{ steps.meta.outputs.version }}"
      echo "Timestamp: ${{ steps.meta.outputs.timestamp }}"

Practical Example: Extracting Version from package.json

steps:
  - name: checkout
    uses: "collabops/checkout@v2"
    with:
      repo-url: "https://<collabops-host>/<workspace>/<repository>.git"

  # Extract version from package.json and store it in the output
  - name: extract-version
    id: pkg
    image: node:18
    run: |
      VERSION=$(node -p "require('./package.json').version")
      echo "app_version=${VERSION}" >> $COLLABOPS_OUTPUT
      echo "Extracted version: ${VERSION}"

  # Tag the Docker image with the extracted version
  - name: build-image
    uses: "collabops/docker-build-push@v1"
    with:
      tags: "my-registry/my-app:${{ steps.pkg.outputs.app_version }}"

Practical Example: Collecting Git Information

steps:
  - name: checkout
    uses: "collabops/checkout@v2"
    with:
      repo-url: "https://<collabops-host>/<workspace>/<repository>.git"
      fetch-depth: "0"    # Full history required (for tag lookup)

  # Extract various information from Git
  - name: git-info
    id: git
    image: alpine/git:2.43.0
    run: |
      cd /workspace/source

      # Latest tag
      LATEST_TAG=$(git describe --tags --abbrev=0 2>/dev/null || echo "v0.0.0")
      echo "latest_tag=${LATEST_TAG}" >> $COLLABOPS_OUTPUT

      # Short SHA
      SHORT_SHA=$(git rev-parse --short HEAD)
      echo "short_sha=${SHORT_SHA}" >> $COLLABOPS_OUTPUT

      # Commit count (since last tag)
      COMMIT_COUNT=$(git rev-list ${LATEST_TAG}..HEAD --count 2>/dev/null || echo "0")
      echo "commit_count=${COMMIT_COUNT}" >> $COLLABOPS_OUTPUT

  # Create image tag from the collected information
  - name: tag-image
    run: |
      echo "Tag: ${{ steps.git.outputs.latest_tag }}"
      echo "SHA: ${{ steps.git.outputs.short_sha }}"
      echo "Commits since tag: ${{ steps.git.outputs.commit_count }}"

Storing Multiple Output Values

Store multiple key=value pairs in $COLLABOPS_OUTPUT, separated by newlines.

- name: collect-metadata
  id: metadata
  run: |
    # Store multiple values at once
    echo "build_number=42" >> $COLLABOPS_OUTPUT
    echo "git_branch=${{ collabops.ref_name }}" >> $COLLABOPS_OUTPUT
    echo "git_sha=${{ collabops.sha }}" >> $COLLABOPS_OUTPUT
    echo "build_date=$(date -u +%Y-%m-%d)" >> $COLLABOPS_OUTPUT

Rules

If you do not specify an id, you cannot reference the outputs of that step.

Only key=value format is supported in $COLLABOPS_OUTPUT.

Do not use spaces or special characters in keys.

Output values can only be referenced by subsequent steps within the same job. Passing output values between jobs is currently not supported.

This follows the same pattern as step output variables in other CI/CD tools.